update sigils (% to ~)
fixed sentences having linebreaks, so when a sentence was outputted, it
looked like more than one. this is because my regex didn't split a
string into lines correctly (was splitting by spaces that came after
newlines, instead of splitting by newlines and spaces after). i also
now catch multiple linebreaks when removing single newlines (not sure
if this is actually needed)
also took care to strip newlines from the ends of generated sentences

the result is each sentence hopefully looks like one